1. Technical Field
The present invention relates to a projector.
2. Related Art
A super luminescent diode (hereinafter also referred to as an “SLD”) is a semiconductor element capable of providing an output up to several tens of mW in the light output characteristic similarly to a semiconductor laser while showing an incoherent property and a wideband spectrum shape similarly to an ordinary light emitting diode. Similarly to a semiconductor laser, the SLD uses a mechanism in which the spontaneous-emission light generated by the recombination of the injected carriers is amplified in accordance with a high gain due to the stimulated emission while proceeding toward a light emitting end surface, and then emitted from the light emitting end surface. It should be noted that unlike the semiconductor laser the SLD requires to prevent formation of the resonator due to the end surface reflection, thereby preventing the laser oscillation from occurring.
As a measure for preventing the laser oscillation, there has been known a configuration of tilting the gain region (optical waveguide) with respect to the emission end surface as shown in, for example, JP-A-2007-165689. In the technology described in the document mentioned above, two such linear optical waveguides tilted with respect to the emission end surface are formed in order for achieving high output power.
In the light emitting element provided with the linear gain regions (optical waveguides) tilted with respect to the emission end surface as described above, the light beams emitted from the plurality of gain regions might proceed in respective directions different from each other in some cases. However, if the SLD is used as a light source of a projector, it is preferable that the light beams emitted from the SLD proceed in the same direction. According to such an SLD, it is possible to make the light axis adjustment in the projector easier.